the domestication of large mammals in some regions and not others has nothing to do with peoples cultural differences. When it boils down to it all it really has to do with is luck. You see not all animals are capable of being domesticated. For instance large carnivores have never been domesticated and farmed because it's too expensive to keep them fed. Some animals like the zebra are way too timid to be domesticated and others such as panda bears often refuse to breed in captivity. Still others like the elephants take so long to grow they aren't worth the energy of farming. So when it comes down to who gets the few animals capable of domestication it's not distributed evenly throughout regions. Like Asia got many potentially domesticatable animals whereas South America got very few. And As far as not domesticating animals being a part of their culture or against their religious beliefs because as soon as other culture such as the Spanish brought over domesticated animals people from cultures that previously had none were quick to jump on the opportunity of getting some so when it comes down to it. It's just sheer luck we're these animals wind up and therefore which culture got them.